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TROPICAL FOWL MITE JN 
THE UNITED STATES 



WITH NOTES ON 
LIFE HISTORY AND CONTROL 



H. P. WOOD 

Entomological Assistant, Investigations of Insects 
Affecting the Health of Man and Animals 




UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT CIRCULAR 79 



Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 



Washington, D. C. Issued January, 1920 



WASHCNQTON : GOVERNMENT PRINTINQ OFFICE : 1920 



il.O»Oi 



OCT 3 1933 



SFqqs 



TROPICAL FOWL MITE^ IN THE UNITED STATES, WITH NOTES ON 
LIFE HISTORY AND CONTROL 



TWO RECORDS of infestations of the tropical fowl mite {Li- 
pony ssus hiirsa JifvlQUQ) on poultry in the United States thus 
far have been reported, one at Beltsville, Md., and the other at Ray- 
mond, 111. In both of these instances the infestations proved rather 
serious and there seems to be no reason why, once established, this 
mite should not prove to be as serious a menace to the poultry in- 
dustry as is the roost mite, and possibly m'ore so. It is urged that 
any occurrence be promptly reported to the Bureau of Entomology 
so that immediate measures may be applied to stamp it out. 

HISTORY IN THE UNITED STATES. 

The first occurrence of the tropical fowl mite in this country was 
reported from Beltsville, Md., April 2, 1917. After this, on January 
24, 1919, the mite was reported from Raj^mond, 111. In neither case 
can the source of the infestation be found. The author, in April 
and May, 1919, went to Raymond and made as thorough an investi- 
gation as could be made in the time allotted. Some of the life his- 
torj^ was worked out and measures of control applied. The mite in 
question was found located on a rather isolated farm and none of 
the poultry of the nearest neighbor was found to be infested. The 
nearest adjoining farm was about 200 yards away, and there were 
no others nearer than one-half mile. The infestation here was first 
discovered in the fall, of 1918. The origin of the infestation could 
not be definitely determined. 

At Beltsville the infestation, according to information obtained 
by Mr. R. W. Wells from Mr. Harry Lamon, of the United States 
Bureau of Animal Industry, was first noticed on some male birds just 
after they were removed from their colony houses to winter quarters. 
This was in the fall of 1916. In the following season the mite was 
apparently eradicated in that locality, the work being carried out 
under the supervision of ]\Ir. Lamon. Just how this infestation 
was obtained is also unknown. 

HISTORY OF THE TROPICAL FOWL MITE IN ITS NATIVE HABITAT. 

We are indebted to Stanley Hirst, of the British Museum of 
Natural History, for most of the knowledge of this species. He re- 

^ Stanley Hirst, of the British Museum, who lias examined the material from Raymond, 
111., states that the species is " apparently a slight variety of Liponyssus hur>>a Berlese." 
152575°— 20 3 



4 Department Circular 79, U. S. Dept. of Agriculture. 

ports it from Africa, China, India, Mauritius, Comoro Islands, 
Bahamas, and South America. It is the common mite on fowls in 
these countries, Dermanyssus gallinae De Geer not being found. He 
reports it from fowls, the starling, the sparrow, a native bird of the 
Comoro Islands called " hibon," and a single specimen from a lizard, 
and states that it is reported to attack man. This mite has been taken 
from fowls suffering from spirochaetosis, and Hirst thinks that it 
transmits the disease. 

THE TROPICAL FOWL MITE AND THE COMMON ROOST MITE COMPARED. 

Liponyssus bursa, the trop- 
ical fowl mite (fig. 1), is con- 
siderably smaller than Der- 
manyssus gallinae, the roost 
mite, and it moves about 
much faster. The posterior 
end of the abdomen in tho 
female is bilobed in most 
specimens. The hairs on the 
dorsum are longer and more 
prominent than in D. galli- 
nae, and the legs are smaller. 
L. hursa is found in the nests 
and on the fowls. D. galllnxie 
is found in cracks of the roost 
and building, in nests, and 
only sparsely on fowls. D. gallinae does not deposit eggs and mo it 
on its host; L. bursa does. D. gallinae feeds at night; L. bursa may 
feed both night and day. 




Fig. 



1. — Tropical fowl mite ; Engorged speci- 
men. Greatly enlarged. 



LIFE HISTORY AT RAYMOND, ILL., MAY, 1919. 

The eggs of L. bursa- are laid either on the host or in the nest. 
Large numbers of them are found in the fluff of the feathers. They 
are not attached, but may adhere by means of a sticky substance. 
They have been found also inside the straw from a nest. Off of the 
host the eggs will hatch in 3 daj'S. The minute larva does not feed, 
but molts in about 17 hours. It is then ready to feed. The first- 
stage nymph will molt in 1 to 2 days. The molting period of the 
second-stage nymph was not determined. 

HABITS. 

While Dermanyssus gallinae has the habit of staying in and about 
the roost most of the time and breeding there, Liponyssus bursa stays 
either on its host or in the nest and breeds in both of these places. 
Xone of these mites is found on the roost. In the case of the English 



I 



Tropical Fowl Mite in the United States. 5 

sparrow most if not all of the breeding takes place in the nests. Very 
few mites are found on sparrows flying around. There are, however, 
enough to start an infestation. Young sparrows not fledged may have 
many mites on them, but after they leave the nest they have only a 
few. Apparently the mite prefers the fluffy down of the hen feathers 
lining the nest to the feathers of the sparrow. This may also be the 
reason why few mites are ever found on young or half-gi-own chick- 
ens. An attempt to infest a young chick devoid of many feathers 
proved a failure. Mites may be found on loose feathers (fig. 2) on 
the floor of the hen house or in shady places in the yard. None was 




Fig. 2. — Hen's feathers infested with the tropical fowl mite. 

found on the grass or in sunny places. Mites on a loose feather placed 
on a hen's back in the sun were so affected that some of them died 
before they could get under the hen's feathers. 

On the fowl the mites are most numerous about the vent. They 
seem to like to accumulate on a few feathers rather than occuj)y many 
feathers. Some feathers will have hundreds of eggs, mites, and 
molted skins mixed with mite excreta. This gives the feathers below 
the vent in an infested fowl a dirty appearance. In heavy infesta- 
tions, while the mites are most numerous about the vent, they may be 
quite generally distributed among the feathers on all sections. In 



6 Department Circular 79, U. S. Dept. of Agriculture. 

feeding, the mites may be found attached in patches, several hundred 
feeding in a space the size of a quarter. Since the adult remains on 
the host it probably feeds intermittently, as it is easily disturbed and 
runs about on the skin. Some mites readily leave an infested fowl, 
Tvhen it is being handled, to crawl on the hands of a person. Mites 
came off of a well-infested rooster placed in a box with an uninfested 
hen and accumulated on the edges of the box. Many hungiy mites 
were found during the daytime on the edges of a box used as a nest. 
Wlien the box was touched large numbers would crawl quickly upon 
the hand. If given a chance some of the mites will pierce tender skin. 
One was observed attached to the back of a lady's hand. The lady 
stated that the mites often bit her. 

HOSTS. 

In examining hosts the best method found was to put them in 
a Mason jar and screw the cover down. If any mites are present 
they will usually come to the cover of the jar or be found on the 
glass or the surface of the host. No mites were found on the brown 
thrush, song sparrow, blackbird, red-headed woodpecker, screech 
owl, quail, or robin.- None was found in a mouse nest or on a mole. 
Mites were found onl}- on poultry, in hen nests, or on loose feathers 
in house or 3'ard, and on English sparrows and in their nests. No 
mites were found on English sparrows or in their nests on any farm 
except one immediately adjoining the original infestation. Here 
a few mites were found on flying English sparrows. It should be 
explained that in the locality studied another mite was more or 
less abundant in some of the English-sparrow nests examined. After 
some stud}' the common species and the tropical mite were easily 
separated. The common species on . the English sparrow does not 
have the bilobed abdomen and the dorsal shield is more rounding at 
the posterior end. 

CONTROL. 

Preliirdno/ry work. — In previous experiments sulphur, soap, and 
water had proved so effective against the depluming mite {Cnemi- 
docoptes gaUinae Railliet) that this was the first remedy tried. A 
hen having a heavy infestation was dipped in a mixture of 2 ounces 
of sulphur, 1 ounce of soap, and 1 gallon of water. This was found 
to be 100 per cent effective. Other treatments which were effective 
in the preliminary work were: Dusting with sulphur, dusting with 
pyrethrum, and dipping in a solution of 1 teaspoonful of 40 per 
cent nicotine sulphate to 1 gallon of water and about one-third 
ounce of soap. Mercurial ointment greatly reduced the numbers 
but did not give 100 per cent efficiency. A solution of prepared lime- 



Tropical Fowl Mite in the United States. 7 

sulphur proved effective in killing the mites but broke down the 
feathers very badly. 

Final ivork. — In the final clean-up an attempt was made to get 
complete eradication. At the present writing this seems to have been 
accouiplished, though more time must elapse before this can be de- 
termined definitely. The poultry houses and chicken coops were 
cleaned and all nesting material was burned. The manure was 
lightly sprayed with carbolineum and then hauled to a garden or 
other sunny place inaccessible to fowls. The inside walls of the 
houses and coops, the roosts, dropping boards, floors, and nests were 
either spraj'ed or painted with carbolineum. 

The fowls were then given a thorough dusting with sulphur, a dust 
can being used and the material being applied liberally. At the time 
of treatment it was raining. The fowls, freshly dusted with sulphur, 
Avere sent out into the rain. No bad results were noted. The owner 
of the flock was sure this treatment would be injurious, but con- 
fessed she saw no injury. The writer believes that from this and 
other experiments the common notion that fowls are injured by get- 
ting wet after being dusted with sulphur is pure fallacy'. The half- 
grown chickens and the mother hens were treated in like mamier. 
The baby chicks w^ere not treated, but the brood coops were given 
clean nesting material and then dusted with sulphur. 

A sheep shed with an open front and a straw-thatched roof was 
found to be used as a breeding place for hundreds of English spar- 
rows. The front was closed with burlap, except for a small opening 
at the ground through which the sheep niiglit enter. After this 
change five sparrows were the greatest number seen in the shed when 
examination was made at night. All sparrow nests that could be 
located were robbed of eggs or young and the nests burned. This 
was done all over the farm. The owners were advised to keep up a 
continuous war against the sparrow by destroying eggs, j'oung, and 
nests whenever found. 

INJURIOUSNESS. 

A continuous heavy infestation of the tropical fowl mite often 
results in the death of the fowl. Sitting hens will leave their nests 
if not relieved of the infestation. Although the disease spirochae- 
tosis has not been reported in- this country, this disease maj' be pres- 
ent nevertheless, and with this mite present the danger of its spread 
would be increased. Some fowls in a flock seem to be more heavily 
infested than others. Apparently those fowls that dust themselves 
most are freest from the mite. Infestations on cock birds appear to 
average heavier than on hens. 



8 Department Circular 79, U. S. Dept. of Agriculture. 

CONCLUSIONS. 

1. The tropical fowl mite (Liponyssus hursa) is a recently intro- 
duced poultry parasite. 

2. The two known infestations in the United States have appar- 
ently been stamped out. 

3. If the pest becomes generally established in this country it will 
undoubtedly constitute a serious menace to the poultry industry; 
hence it is important that it be excluded or, if introduced, promptly 
eradicated. 

4. Since this mite feeds and- breeds on poultry it could be intro- 
duced readily into the country and disseminated through the ship- 
ment of infested stock. 

5. It maj^ be stamped out either by dipping fowls in sulphur, soap, 
and water, or by giving them a heavy dusting with sulphur. At the 
same time the houses, especially the nests, floors, and dropping 
boards, must be treated with carbolineum. 

6. A continuous war against the English sparrow should be insti- 
tuted in a locality where the mite is discovered. Nests should be 
robbed and destroyed by fire and the nesting places eliminated. 



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